The present invention relates to a hairdressing device having a hand unit, which has a cylindrical hair roller driven to rotate by a motor and a hot-air nozzle blowing at the hair roller at right angles to the axis of rotation of the hair roller, in which negative pressure prevails at intake openings of the cylindrical hair roller, the negative pressure being generated by a blower that is disposed in a blower housing and communicates with the hand unit via a hose. The air aspirated by the blower via the intake openings of the cylindrical hair roller, flowing through the blower housing and then flows out of the blower housing.
A hairdressing device of this type is known (EP-B1-0 052 325, DE-U-87 17 038.8). In the device disclosed in this patent, cooling of the blower motor is provided by the air flow entering the blower housing via the hose and exiting from it into the surroundings of the blower housing via suitable outlet openings of the blower housing. The negative pressure required to apply a hair or a strand of hair to the surface of the rotating cylindrical hair roller in the known hairdressing device is accordingly generated in a manner similar to that of a vacuum cleaner. To dry the hair applied to or wound on the surface of the cylindrical hair roller, air is aspirated from the surroundings through intake slits provided in the housing of the hand unit, by means of a further blower provided in the hand unit, and this air is carried to the hot-air nozzle via suitable air heaters. The known device has the disadvantage that the necessary separation between the negative pressure air loop and the drying air loop, required for effective drying, makes for a complicated construction of the known hairdressing device. A blower in the hand unit is necessary to supply air to the hot-air nozzle, and its additional weight makes the hand unit harder to manipulate. The persons whose hair is being dressed are exposed to constant noise, which impairs their comfort considerably.
German Patent 37 38 968 discloses a hairdressing device in which a closed air loop is provided between the intake openings of a rotatable hollow body and a blow-out nozzle with air blow-out slits, blowing vertically against the hollow body. The air aspirated via the suction openings of the hollow body is carried via a flexible hose to the suction side of a central unit. A radial fan carries the air, delivered to the suction side of the central unit, via the hose, to the compression side of the central unit. This side has outlet connection pieces, in each of which an air heater is disposed. The air, heated in the air heaters, is supplied via a further hose to the air blow-out slits of the blow- out nozzle. This known hairdressing unit has the disadvantage that it has a single self-contained air loop. The moisture given up by the hair applied to the hollow body reaches the central unit, via the suction openings and the flexible hose, and is heated by the air heaters in the central unit. Via the blow-out nozzle, the resultant warm, moist air is then blown back on to the hair to be dried. A closed air loop of this kind rapidly becomes saturated with moisture, so that no further drying action can take place.